Total Synthesis of (+)-Aloperine. Use of a Nitrogen-Bound Silicon Tether in an Intramolecular Diels−Alder Reaction
1999; American Chemical Society; Volume: 121; Issue: 4 Linguagem: Inglês
10.1021/ja983013+
ISSN1943-2984
AutoresArthur D. Brosius, Larry E. Overman, Lothar Schwink,
Tópico(s)Asymmetric Synthesis and Catalysis
ResumoEnantioselective total syntheses of aloperine (1), N-methylaloperine (2), and N-allylaloperine (3) are reported. The central element of the synthetic strategy is an intramolecular Diels−Alder reaction in which the cycloaddends are tethered by a N-silylamine linkage. The total synthesis of 1 proceeds from commercially available 3-hydroxypiperidine hydrochloride (54) and (R)-pipecolinic acid (35) by way of nine isolated and purified intermediates. The synthesis is sufficiently efficient that gram quantities of (+)-aloperine (1) can be readily prepared. Early exploratory studies also introduced a convenient method for tethering cycloaddition partners with a sulfonamide unit to realize the intramolecular Diels−Alder cycloaddition of a vinylsulfonamide: 45 → 46.
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